This invention is directed to a method and apparatus for deep drawing a metal blank to form a finished product, and in particular, it is directed to forming a one-piece finished product by moving, material from the product bottom portion and into the product sidewall portion during the deep drawing operation.
Various methods and tooling arrangements have been used in the past to deep-draw and/or iron a metal blank into a one-piece finished product. For example, such metal blanks are deep-drawn into containers for holding food and beverage products as well as non-eatable products. Automotive parts such as oil filters, air conditioner accumulators; and charcoal canisters are also manufactured using deep-drawing technology. Such past apparatus and methods are shown in the patents listed in the information disclosure statement filed with the present patent application. For instance, U.S. Pat. No. 5,209,099, granted to Saunders on May 11, 1993, discloses typical state-of-the-art can forming methods and apparatus comprising a die, a clamp, and a draw punch arrangement used in combination to form a metal blank into a one-piece container; the formed one-piece container having an open end that receives a lid in a downstream manufacturing step. Saunders teaches clamping the cut metal blank against the surface of the die while the draw punch is extended to force portions of the metal blank into the die cavity. In such a deep drawing operation, the draw punch typically approximates the desired size and/or shape of the finished product bottom, and the punch first forces the corresponding bottom portion of the metal blank into the die cavity with little or no working while the sidewall portions of the blank are worked within the die cavity to form the sidewall of the one-piece finished product. As a result of such unequal working along different portions of the metal blank, the finished product has a bottom thickness that is relatively close to the original metal blank thickness, and the product sidewall is greatly reduced in thickness when compared to the original blank thickness.
Although such manufacturing processes produce a one-piece product that is functionally sound from a user viewpoint, the drawing processes of the past are wasteful from a manufacturing viewpoint in that past methods fail to use excess bottom material during the manufacturing process. Therefore, recognizing this, the present invention is directed to providing a method and apparatus that more efficiently uses the metal blank material by moving excess metal from the bottom portion of the deep-drawn product, and into the sidewall portion of the product.
It is therefore an object of the present invention to provide a method and apparatus for improving the use of available material in a product blank during a deep drawing operation.
It is another object of the present invention to provide a method and apparatus that moves excess material from a formed product bottom to the product sidewall during a deep drawing operation.
It is still another object of the present invention to form a deep-drawn product from a product blank having less blank material when compared with a corresponding product blank used in the past.
Other objects and advantages of the present invention will become apparent as a description thereof proceeds.
In satisfaction of the foregoing objects and advantages, the present invention provides apparatus, and a method of using the apparatus, to draw a product blank into a product. The apparatus includes a die having a cavity to receive the product blank being drawn into the desired product, a clamp adapted to apply an adjustable force against the product blank during the drawing operation, and a mandrel comprising a plurality of nested tool segments, each nested tool segment independently extendable to engage, draw, and form a portion of the product blank within the cavity, the combination of extended nested tools cooperating to form the desired product.